Textbooks are Wrong; Sun Isn't Ordinary
by Team 25763
Guillermo Gonzales, of the University of Washington, who is taking part in the search for extraterrestrial life (SETI), claims, "Unless astronomers narrow down their search to stars as exceptional as the Sun, they are wasting much of their time." One characteristic of our sun is that it is a single star, whereas other stars are part of multiple-star systems. Gonzalez has discovered that the Sun has 50% more heavy elements than other stars its age and type. In addition, it is in the top 10% of massive stars in its neighborhood.
The most unusual characteristics of the Sun are its orbit, and it's corotation radius. It has an orbit that is much less elliptical (meaning its orbit is more circular, less oval) than stars similar to it. It is also orbiting at about the same angular speed as the stars in our galaxy (also known as the corotation radius). Gonzalez says that all of these characteristics made it possible for intelligent life to form on Earth. We needed a stable planetary orbit, which does not usually happen around a multiple-star system. Since the Sun is a massive star, it produces heavy elements, which are necessary to form planets like Earth. In addition, a steady light output is a key to life.
Ultraviolet Picture of the Sun
The circular orbit of the Sun prevents it from diving into the inner Galaxy, into a place where deathly supernovae are commonly found. Since the Sun is near the corotation radius, it prevents the Sun from being exposed to supernovae, which would be common if it wasn't close to the corotation radius. Just because of that one factor (being close to the corotation radius), that rules out 95% of all stars in the Galaxy! Gonzales says, "There are fewer stars suitable for intelligent life than people realize."
Some astronomers do disagree with Gonzalez though, says researcher Dan Werthimer of the University of California at Berkeley. He believes that our sun is average, meaning that you don't need a star exactly like our sun for life.
©1999 ThinkQuest Team 25763. All rights reserved.
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